Boil the Pasta: Bring a large pot of salted water to a rolling boil. Toss in the fettuccini and cook according to package instructions until al dente, about 8-10 minutes. Drain and set aside, reserving a cup of the pasta water.
Build the Alfredo Sauce: Pour in the heavy cream and half-and-half, stirring to combine. Bring to a gentle simmer, allowing it to thicken. Add the Italian seasoning and season with salt and pepper to taste.
Add the Kick: Stir in the Buffalo sauce, adjusting to your heat preference.
Combine it All: Add the drained pasta and Parmesan cheese, tossing gently. If the sauce is too thick, add reserved pasta water until desired consistency is achieved.
Final Touches: Return the sliced chicken to the skillet and toss everything together one last time over low heat to warm through.
Serve and Garnish: Spoon the pasta onto plates, garnishing with fresh parsley and extra Parmesan if desired.
Notes
Serve with a side salad or roasted vegetables. Store leftovers in an airtight container for up to 3 days.